In manufacturing a semiconductor device, a liquid processing such as a cleaning processing or a wet etching processing is performed on a substrate such as a semiconductor wafer. As a processing liquid supply mechanism of a substrate liquid processing apparatus for performing the liquid processing, a processing liquid supply mechanism including a tank in which the processing liquid is stored, a circulation path drawn from the tank and then returning to the tank, a branch line branched from the circulation path, and a liquid processing unit (module) having a nozzle ejecting the processing liquid supplied from the circulation path through the branch line to a substrate has been known.
Japanese Patent Laid-Open Publication No. 2006-080547 discloses that the substrate liquid processing apparatus configured as described above includes an upper nozzle and a lower nozzle which simultaneously supply the same processing liquid to an upper surface and a lower surface of the substrate, respectively. The processing liquids supplied from the upper nozzle and the lower nozzle to the substrate are inevitably mixed within the liquid processing unit and are discharged from a liquid processing unit. The discharged processing liquid is recovered and reused. The substrate liquid processing apparatus disclosed in Japanese Patent Laid-Open Publication No. 2006-080547 commonly includes most components (for example, a tank and a circulation path) of the processing liquid supply mechanism which supplies the processing liquid to the upper nozzle and the processing liquid supply mechanism which supplies the processing liquid to the lower nozzle. For this reason, the recovered processing liquid is supplied to the upper and lower surfaces of the substrate without being differentiated.
Generally, however, the state of the substrate is not the same on the upper and lower surfaces. For this reason or other reasons, there may be a case in which a state required for the liquid to be supplied to the upper surface of the substrate and a state required for the liquid to be supplied to the lower surface of the substrate are different from each other. The apparatus of Japanese Patent Application Laid-Open No. 2006-080547 may not cope with the requirements.